1. Field of the Invention
The present invention relates to an intelligent intersection determination apparatus and method to determine a location of a mobile station in a cell or similar radio coverage service area, and in particular, but not exclusively, an intelligent intersection apparatus and method to determine a location estimate of a mobile station based on a cost function analysis.
2. Description of the Related Art
A cellular telecommunications system is based around cells or similar radio coverage and/or service areas. Examples of cellular telecommunications systems include standards such as the GSM (Global System for Mobile communications) or various GSM based systems (such as GPRS: General Packet Radio Service), AMPS (American Mobile Phone System) or DAMPS (Digital AMPS) or WCDMA (Wideband Code Division Multiple Access) and TDMA/CDMA (Time Division Multiple Access/Code Division Multiple Access) in UMTS (Universal Mobile Telecommunications System), IMT 2000 and so on.
In the cellular telecommunication system, a base transceiver station (BTS) serves mobile stations or similar wireless user equipment (UE) via an air or radio interface. A base station provides a coverage area that can be defined as a certain geographically limited area referred to as a cell. The size and shape of cells may vary from cell to cell. Several cells may also be grouped together to form a larger service area.
Each of the cells can be controlled by an appropriate controller apparatus. For example, in a GSM radio network the base station may be connected to and controlled by a base station controller (BSC) of a base station subsystem (BSS). The BSC/RNC (radio network controller) may be then connected to and controlled by a mobile switching center (MSC). Other controller nodes may also be provided, such as a serving GPRS support node (SGSN). The MSCs of a cellular network are interconnected and there may be one or more gateway nodes connecting the cellular network, for instance, to a public switched telephone network (PSTN) and other telecommunication networks, such as the Internet and/or other packet switched networks. The mobile station may also be in communication with two or more base stations of the cellular telecommunication system at the same time. The two or more base stations may be connected to the same controller or different controllers.
The cellular telecommunication system can also be employed for provision of location information concerning the mobile station and the user thereof. More particularly, the cells or similar geographically limited service areas facilitate the cellular telecommunications system to produce at least a rough location information estimate concerning a current geographical location of the mobile station, as the cellular telecommunications system is aware of the cell within which the mobile station is currently linked. Therefore, it is possible to determine the geographical location in which the mobile station is likely to be at a given moment. This information is available also when the mobile station is located within the coverage area of a visited or “foreign” network. The visited network may be capable of transmitting location information of the mobile station back to the home network, e.g., to support location services or for the purposes of call routing and charging.
The mobile station is able to move within the cell and also from one cell coverage area to another cell coverage area. Thus, the location of the mobile station may vary in time as the mobile station is free to move within the service area of the system. Accordingly, accurate information concerning the geographical location of a mobile station is desired. In addition, the United States Federal Communication Commission (FCC) has mandated that wireless service providers have to implement location technologies that can locate the mobile station users who are calling to E911 emergency center.